At least 20 children have been found dead at the scene of a fire in a shelter for children near Guatemala City, officials said.

A spokesman for Guatemala’s volunteer fire departments, Mario Cruz, said that firefighters were still extinguishing parts of the blaze. About two dozen people were being treated for injuries.

The national police department said a total of 41 people had been injured, while the country’s health ministry said that 14 were in a serious condition with severe burns.

Dr Carlos Soto, the director of the Roosevelt Hospital where some were being treated, said the most severe cases, all apparently girls, had suffered life-threatening burns.

The shelter has been criticised for overcrowding, alleged abuse and escapes in the past.

The prosecutor for children’s rights, Abner Paredes, said initial reports suggested the blaze started when some occupants began setting fire to mattresses in the shelter, known as the Virgin of the Assumption Safe Home.

There were reports of escape attempts on Tuesday at the shelter, which was created to house children who were victims of abuse, homelessness or who had completed sentences at youth detention centres and had nowhere else to go.

While the shelter was built to house 500 children and adolescents, it held an estimated 800 at the time of the fire.